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| Effect of Amount of Thermal ε Martensite on Shape Memory Effect of Co-30Ni Alloy |
| CHEN Ping, YANG Xiao, PENG Hua-bei, WEN Yu-hua |
| College of Manufacturing Science and Engineering,Sichuan University, Chengdu 610065, Sichuan ,China |
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Abstract To know the origin of shape memory effect in Co-Ni alloys showing ε martensitic transformation, different amounts of thermal-induced ε martensite were obtained before deformation through controlling the deforming temperatures. The evolutions of the pre-existing thermal-induced ε martensite and its effect on stress-induced ε martensitic transformation were studied during deformation by OM and XRD, and the shape memory effect was measured by bending method. The results showed that the shape memory effect of Co-Ni alloys resulted from the stress-induced ε martensitic transformation, rather than the coalescence of thermal martensite. The low yield strength accounted for its poor SME. The pre-existing thermal ε martensite can increase the yield strength and thus enhance shape memory effect in Co-Ni alloys.
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Received: 09 April 2014
Published: 26 June 2014
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| Fund:National Natural Science Foundation of China |
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| [7] |
H. Yang, Y.N. Liu. Factors influencing the stress-induced fcc?hcp martensitic transformation in Co–32Ni single crystal [J]. Acta. Mater., 2006, 54: 4895-4904.
|
| [5] |
W.M. Zhou, Y. Liu, B.H. Jiang, X. Qi. Shape Memory Effect in Co-Ni Polycrystalline Alloys [J]. Mater. Sci. Forum, 2005, 475-479: 2029-2032.
|
| [11] |
W.B. Liu, Y.H.Wen, N. Li, S.Z. Yang. urther improvement of shape memory effect in a pre-deformed Fe–Mn–Si–Cr–Ni–Nb–C alloy by smaller NbC precipitated through electropulsing treatment [J]. J. Alloys Compd., 2009, 472: 591-594.
|
| [2] |
W.M. Zhou, Y. Liu, B.H. Jiang, X. Qi, Y.N. Liu. Magnetoelastic and thermoelastic shape memory effect in a Co–Ni single crystal [J]. Appl. Phys. Lett., 2003, 82: 760-762.
|
| [8] |
Y.H. Wen, H.B. Peng, P.P. Sun, G. Liu, N. Li. A novel training-free cast Fe–18Mn–5.5Si–9.5Cr–4Ni shape memory alloy with lathy delta ferrite [J]. Scripta Mater., 2010, 62: 55-58.
|
| [13] |
Q. Yang, Q. Yu, H.B. Peng, Y.H. Wen. Effects of Thermally Induced Cyclic γ??? εTransformation on Shape Memory Effect of a Quenched FeMnSiCrNi Alloy [J]. Adv. Eng. Mater., 2013, 15: 697-703.
|
| [4] |
Y.N. Liu, H. Yang, Y. Liu, B.H. Jiang, J. Ding, R. Woodward. Thermally induced fcc?hcp martensitic transformation in Co–Ni [J]. Acta. Mater., 2005, 53: 3625-3634.
|
| [9] |
A. Sato, E. Chishima, K. Soma, T. Mori. Shape memory effect in γ? ? transformation in Fe-30Mn-1Si alloy single crystals [J], Acta. Metall., 1982, 30: 1177-1183.
|
| [6] |
W.M. Zhou, Y. Liu, B.H. Jiang, P.N. Zhou. Effect of adding Si on shape memory effect in Co–Ni alloy system [J]. Mater. Sci. Eng., 2006, A438-440: 468-471.
|
| [1] |
H.C. Shin, S.H. Lee, J.H. Jun, C.S. Choi. Martensitic transformation kinetics and shape memory effect in Co-Ni alloys [J]. Mater. Sci. Technol., 2002, 18: 429-432.
|
| [3] |
Y.N. Liu, H. Yang, G. Tan, S. Miyazaki, B.H. Jiang, Y. Liu. Stress-induced FCC ? HCP martensitic transformation in CoNi[J]. J. Alloys Compd., 2004, 368: 157-163.
|
| [12] |
X. Min, T. Sawaguchi, X. Zhang, K. Tsuzaki. Reasons for incomplete shape recovery in polycrystalline Fe-Mn-Si shape memory alloys. Scripta Mater., 2012, 67: 37-40.
|
| [14] |
Y. Tomota, Y. Morioka, W. Nakagawara. Epsilon martensite to austenite reversion and related phenomena in Fe-24Mn and Fe-24Mn-6Si alloys [J]. Acta. Mater., 1998, 46: 1419-1426.
|
| [10] |
S. Kajiwara. Characteristic features of shape memory effect and related transformation behavior in Fe-based alloys [J]. Mater. Sci. Eng., 1999, A273-275: 67-88.
|
|
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2014, Vol. 21 
